There are probably as many ideas as to what it means that mankind was created in the image of God as there are people who believe that we were. Nonetheless, I offer one, courtesy of the following section of a Max Weber essay on objectivity in social science and policy:

“The transcendental presupposition of every cultural science lies not in our finding a certain culture or any “culture” in general to be valuable but rather in the fact that we are cultural beings, endowed with the capacity and the will to take a deliberate attitude towards the world and to lend it significance.” (Methodology of Social Sciences [2011] p. 81)

As opposed to the rest of creation, we have the co-creative capacity to lend the world significance through our value judgments and our actions. By the way, Weber was a polymath who is claimed by sociologists and economists, among others, but he was never to my knowledge considered a theologian. Think about it. That is all.